You have a bomb to defuse, and your time is running out! Your informer will provide you with a circular array code of length of n and a key k.
To decrypt the code, you must replace every number. All the numbers are replaced simultaneously.
If k > 0, replace the ith number with the sum of the next k numbers.
If k < 0, replace the ith number with the sum of the previous k numbers.
If k == 0, replace the ith number with 0.
As code is circular, the next element of code[n-1] is code[0], and the previous element of code[0] is code[n-1].
Given the circular array code and an integer key k, return the decrypted code to defuse the bomb!
Example 1:
Input: code = [5,7,1,4], k = 3
Output: [12,10,16,13]
Explanation: Each number is replaced by the sum of the next 3 numbers. The decrypted code is [7+1+4, 1+4+5, 4+5+7, 5+7+1]. Notice that the numbers wrap around.
Example 2:
Input: code = [1,2,3,4], k = 0
Output: [0,0,0,0]
Explanation: When k is zero, the numbers are replaced by 0.
Example 3:
Input: code = [2,4,9,3], k = -2
Output: [12,5,6,13]
Explanation: The decrypted code is [3+9, 2+3, 4+2, 9+4]. Notice that the numbers wrap around again. If k is negative, the sum is of the previous numbers.
Constraints:
n == code.length
1 <= n <= 100
1 <= code[i] <= 100
-(n - 1) <= k <= n - 1
Solution:
class Solution {
public int[] decrypt(int[] code, int k) {
int n = code.length;
int[] res = new int[n];
if (k == 0) return res;
if (k > 0) {
for (int i = 0; i < n; i ++) {
int p = 1, v = 0;
for (int j = (i + p) % n; p <= k; p ++, j = (i + p) % n) {
v += code[j];
}
res[i] = v;
}
} else {
for (int i = 0; i < n; i ++) {
int p = -1, v = 0;
for (int j = (i + p + n) % n; p >= k; p --, j = (i + p + n) % n) {
v += code[j];
}
res[i] = v;
}
}
return res;
}
}